Air conditioning system



VNITED Ares MR COITIU lPaui M. Raigorodsky, Tulsa, 'Okla.

Application January 23,

(cu. G2-ll'l9) Claims.

This invention relates to certainnew and useful improvements in air conditioning systems.

In an air conditioning system, the minimum temperature required in the evaporator, in order 5 to cool and de-humidify the air, is approximately 50 F. At this temperature, the relative humidity .of the conditioned air at 80 F. can be reduced to about 35% which is well within the comfort zone as shown by the comfort chart of the Harvard School of Public Health.

- In theordinary manufacture of ice, ammonia is used in the absorption system and a brine is used as the circulating medium. An important object of this invention is to utilize individual l5 hydrocarbons for the refrigerant and absorbent and it has been found to be highly practical to utilize butane as the refrigerant and octane as the absorbent, or equivalent of these elements. With r,the use of butane it is possible to obtain temperatures in the evaporator as low as 35 F., to 40 F. when operating the evaporator at atmospheric pressure. Octane has .a relatively low-boiling point which enables the still to be operated at a temperature around 250 F., thus avoiding disintegration of the absorbent with the. resultant coking of pipes and tubes. However, the boiling point of octane is sufilciently high as compared with that of butane that when using a combination of these two hydro-carbon by-products, a high degree of separation may be obtained when using only single flash vaporization. This system eliminates the necessity for an elaborate fractionating apparatus and reduces the fuel consumption to a minimum. While butane and: oc-

35 tane are designated as preferred examples of refrigerant and absorbent, respectively, for use in this invention, other individualhydrocarbons -or mixtures thereof may be utilized and such hydrocarbons are best characterized as a hydrocarbon absorbent-refrigerant consisting of a hydrocarbon refrigerant and a hydrocarbon absorbent, said refrigerant being substantially completely separable from said absorbent by flash vaporization and substantially completely soluble in said absorbent without compression. The use of hydrocarbon refrigerants and absorbents, as thus characterized, eliminates the necessity for mechanical compression means in t e refrigerant cycle and thereby greatly simplifies construction of this system over other systems.

The refrigerant is further characterized as of relatively high vapor pressure as compared to the absorbent but-completely liquefiable under nor-' mal atmospheric temperatures, thereby permitting utilization of ordinary water cooling for convention is better understood; the same consists 1 pipe section 5 that enters the lower end of a 1935, Serial rm. 3,177

densation of the refrigerant and eliminating the need for special low temperature condensing mediums or compressors.

It is therefore an important object of this invention to utilize'circulating mediums for the air'conditioning apparatus that are practical and economical in the use thereof.

With the above and other objects in view that will become apparent as the nature of the inin the novel form, combination and arrangement, of parts hereinafter more fully described, shown in the accompanying drawing and claimed.

The accompanying drawing diagrammatically illustrates the air conditioning system.

Referringmore in detail to the accompanying drawing, the reference character i designates a. heater or boiler and while the heating medium therefor may be of any preferred character, the same is illustrated as being a gas burner 2, supplied by a pipe 3 in communication with a suitable source of gas supply. The heater or boiler i incloses a coil pipe 0 arranged above the burner i, the upper end of the coil t continuing in a still 6 with the pipe section 5 provided with a coil ll-in the lower end of the still that continues in a pipe section 0 returning to and in communication with the coil t in the boiler i.

The steam coil 1 in the lower end of the still 6 furnishes heating for the distillation .process and steam condensation returns by gravity through the pipe 8 to the boiler i. A constant temperature of about 250 F. is maintained in the still by controlling'the steam pressure through the medium of a steam line 9 indicated by dotted lines that forms communication between the pipe section 5 and the gas valve ill .in the gas supply pipe 3. The valve stem embodies a diaphragm acted upon by steam pressure for regulating the flow of gas to the burner 2.

The water cooling apparatus of the system embodies a cooling tower Ill having an outletpipe it with a pump i3 set therein for drawing water from the tower and forcing the same through the 5 pipe it into the coil i i housed in the absorber and cooler casing l5, the coil M extending by way of the pipe it to the .0011 ll housed in the con-' denser casing N and from said coil H, the pipe 18 returns to the cooling tower ii.

,The temperatures, pressures and volumes are representative of a unit of three 3),- tons per day 5 capacity, an equivalent of 864,000 13. t. 11. per day. In tracing the flow through the system, it

will be found that a mixture 30 mol. percent iii butane and '10 mol. percent octane, called the rich oil, enters the still at a temperature of 200 F. to 210 F. and is heated up to a temperature of 250 F. by the steam heating sections. The resultant vapors are butane and some octane due to the existing partial pressures. The vapor enters the dephlegmator section of the still where the temperature is reduced sufiiciently to condense out practically all of the entrained octane. The butane vapor escapes through the upper end of the still 6 by way of the pipes I9 having a control valve therein and enters the condenser casing l8 where the same is liquefied by heat exchange with cooling water solely under the self-generated pressure of the butane vapors, the butane liquid then flowing from the condenser casing I8 by way of the pipe 2| to the head of an evaporator 22. The liquid butane is then expanded in the evaporator reducing refrigeration and flows therefrom by way of the pipe line 23 to the absorber and cooler casing l5 where it is absorbed by the octane or lean oil from the still at a pressure lower than the aforesaid self-generated pressure. The octane or lean oil in the absorber and condenser casing 15 is received by way of the pipe 24 forming communication between the lower end of the still 6 and the heat exchanger 25, the pipe 26 in the heat exchanger extending to the absorber and cooler casing I5. A pipe 21 forms communication between the cooler casing 15 and the heat exchanger and has a pump 28 set therein for drawing the cold rich oil from the absorber and cooler casing and pre-heating it by forcing the same through the heat exchanger prior to return to the still 6. Part of the oil drawn from the absorber and cooler casing is delivered by way of the pipe 29 that forms communication between the pipe 21 and reflux condenser coil 3!] in the dephlegmator section of the still, the pipe 3| extending from the reflux condenser coil 36 communciating with the pipe 32 that extends to the still 6. A pipe 33 forms communication between the heat exchanger 25 and the return pipe 32.

A blower 34 is in communication with the evaporator 22 and circulates conditioned air flowing over the evaporator by way of the air ducts 35 into the air conditioned enclosure 36, the circulation and return of air from the air conditioning closure being by way of the air return ducts 31 to the evaporator.

The temperature of the evaporator is regulated -by the pipe line connection 38 forming communication between the evaporator 22 and the diaphragm operated valve 39 set in the pipe 21 to control the action of the pump 28.

Air conditioning is accomplished by continuously circulating the air from the air conditioned enclosure through the evaporator. As the air passes through the enclosure, it absorbsthe heat and becomes humidified, due to the moisture given off by the occupant and also by the excess humidity in thefresh air being admitted to the enclosure from the outside. The temperature of the air as it passes through the evaporator or cooler is reduced to a few degrees below the dew-point where condensation takes place, thereby reducing humidity.

Obviously, the point at which the air is conditioned and heretofore referred to as the evaporator 22 may be identified as an air conditioning station, and similarly, the still reflux condenser, heat exchanger, cooler, condenser, etc., may be referred to as stations and the pipe lines connecting the stations effecting the cycles of operation.

From the above detailed description of the invention, it is believed that the construction and operation thereof will at once be apparent, and while there is herein shown and described the preferred embodiment of the invention, it is nevertheless to be understood that minor changes may be made therein without departing from the spirit and scope of the invention as claimed.

I claim:-

1. A method of refrigeration comprising vaporizing and separating butane from a mixture of butane and octane by flash vaporization, condensing the resulting butane vapors solely under the self-generated pressure of said vapors and at normal temperatures, expanding the resulting butane condensate to thereby produce a refrigerating effect, absorbing the expanded butane vapors in said octane and subjecting the resulting mixture of butane and octane to the aforesaid flash vaporization.

2. The method of refrigeration which comprises evaporating a liquid hydrocarbon refrigerant of relatively low boiling point, directly absorbing the vapors of said refrigerant solely under the self generated pressure of said vapors in a liquid hydrocarbon absorbent of relatively high boiling point, separating the refrigerant from the absorbent by flash vaporization and condensing the refrigerant solely under the self generated pressure of the vapors thereof.

3. The method of refrigeration which comprises evaporating a liquid hydrocarbon refrigerant of relatively low boiling point, directly absorbing the vapors of said refrigerant solely under the self generated pressure of said vapors in a liquid bydrocarbon absorbent of relatively high boiling point, subjecting the mixture of absorbent and refrigerant to flash vaporization to separate said refrigerant in vapor form from said absorbent, utilizing said mixture of absorbent and refrigerant prior to separation from each other as in indirect cooling medium for said refrigerant vapors separated from said absorbent, and condensing the last mentioned refrigerant vapors solely under the self-generated pressure thereof to produce said liquid hydrocarbon refrigerant.

4. The method of refrigeration which comprises evaporating a liquid hydrocarbon refrigerant of relatively low boiling point, directly absorbing the vapors of said refrigerant solely under the self-generated pressure of said vapors in a liquid hydrocarbon absorbent of relatively high boiling point in the presence of an indirect cooling medium, subjecting the mixture of absorbent and refrigerant to flash vaporization to separate said refrigerant in vapor form from said absorbent, utilizing said mixture of absorbent and refrigerant prior to separation from each other as an indirect cooling medium for the refrigerant vapors separated from said absorbent, and condensing the last-mentioned refrigerant vapors solely under the self-generated pressure thereof to produce said liquid hydrocarbon refrigerant.

5. The method of refrigeration which comprises evaporating liquid butane, directly absorbing the butane vapors under their self-generated pressure in liquid octane, separating the butane from the octane by flash vaporization, and condensing the butane vapors resulting from the separation solely under their self-generated pressure.

PAUL M. RAIGORODSKY. 

